Electronic devices, such as mobile phones, has been recently demanded to be thin, accordingly requiring thin loudspeakers accommodated in cases of the devices.
In order to allow a conventional loudspeaker disclosed in patent document 1 below to be thin, a magnet forming a magnetic circuit necessarily has a small size. Such a small magnet provides inevitably a small magnetic force, accordingly generating a small sound output. Hence, the magnet cannot be small, and accordingly, prevents the loudspeaker from being thin.
Patent Document 1: Japanese Patent Laid-Open Publication No. 2005-51283